/*
 * Copyright (c) 2025, Your Name.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the Institute nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * This file implements the extensions to the protothreads library.
 *
 * Author: Your Name <your.email@example.com>
 */

#include "pt_ext.h"

/**
 * Global tick counter.
 *
 * This variable is used to track system ticks. It should be incremented
 * by the system tick interrupt or a similar mechanism.
 */
volatile unsigned int pt_ticks = 0;

/**
 * Increment the system tick counter.
 */
void
pt_ticks_inc(void)
{
    pt_ticks++;
}

/**
 * Get the current system tick counter.
 *
 * \return The current tick count.
 */
unsigned int
pt_ticks_get(void)
{
    return pt_ticks;
}

/**
 * Check if timeout has occurred, handling tick counter overflow.
 */
int
pt_is_timeout(unsigned int start, unsigned int end, unsigned int timeout)
{
    return (end - start) >= timeout || 
           ((end < start) && (UINT_MAX - start + end + 1) >= timeout);
}

/**
 * Initialize the protothreads extensions.
 *
 * This function resets the global tick counter to zero.
 */
void
pt_ext_init(void)
{
    pt_ticks = 0;
}
